The present invention relates to anti-vortex and vapor-ingestion-suppression devices, and more particularly to an anti-vortex vapor-ingestion-suppression device that works in various gravity environments.
Many space vehicles, generally use a liquid propellant which is stored in storage tanks and fed into engines during take off and flight in space. The liquid must be moved from the storage tanks to the engine in an efficient manner. First, vapor or gas cannot be allowed to enter the engines in any great amount or too early in the ignition process. If gas is introduced into the engines, it may cause a stall or other malfunctioning of the engine that may increase the possibility of engine failure. It is generally known in the art to provide a device that is be placed in the propellant storage tanks which will reduce the acquisition of gas into the engine. Second, it is desirable to empty the storage tanks as completely as possible during an engine burn and flight to reduce re-entry weight and increase vehicle payload. Typically, a portion of liquid propellant still remains in the tank, thereby increasing the vehicle weight and reducing the maximum payload of the vehicle.
One solution to vapor ingestion is to provide a screen that encompasses the interior area of the tank or at least a portion thereof. Therefore, fluid is wicked through the screens by capillary action, and vapor or gas bubbles are prevented from flowing through the screens by the bubble point pressure of the fluid screen system. Screen systems are made most advantageous only for storage tanks being used in low gravity and are less useful in environments where significant gravity is present. Additionally, the screen systems typically cannot be used with certain liquid propellants such as hydrogen peroxide due to material incompatibility between H2O2 and typical screen materials. The increased surface area of the screens adds more area for chemical reactions where the liquid propellant may decompose.
Other systems provide vanes extending a distance from the sump of the tank towards the walls of the storage tank. These vanes help bring liquid propellants to the outflow area of the storage tank through capillary action. Furthermore, the vanes help reduce the ingestion of gas bubbles into the engine of the vehicle. The vanes used in known vapor ingestion suppression systems, however, are for very low flow rates and cannot provide substantial vapor ingestion suppression at the higher flow rates of many reusable space craft.
Thus, the generally known anti-vapor ingestion systems include several drawbacks. Additionally, known systems allow too much fuel to be left in the storage tanks thereby decreasing the efficient use of the fuel stored in the tanks and decreasing the payload for a similarly sized tank and vehicle. Additionally, the known systems increase the breakdown of certain propellant fluids into gas and non-fuel or inert substances. Therefore, there is a need in the art for a device that will allow for anti-vortexing of the fuel as it leaves the tank, and to increase ingestion of liquid propellant into the sump and outlet, thereby increasing the efficiency of the storage tanks and decreasing the possible ingestion of gases.
In a first preferred embodiment of the present invention, a storage vessel has an outlet and a liquid propellant management system adjacent the outlet. The liquid propellant management system reduces a dip and a vortex of a liquid, which reduces vapor ingestion into the outlet of the tank in both high gravity environments and low gravity environments. The liquid propellant management system has a first vane with bores, a first end a second end. A plate is also included with bores having a first side and a second side where the first side is operably associated with the first vane. The system also has a second vane operably associated with the second side of the plate. The first vane is adapted to substantially reduce a vortex of a liquid. The plate substantially reduces a dip of a liquid due to frictional energy dissipation, and the second vane provides frictional energy dissipation and substantially wets the plate with a liquid in the tank.
In a second preferred embodiment of the present invention, a liquid propellant management device for use in a liquid storage tank has a first member to suppress the formation of a vortex in a liquid exiting the tank. A plate operably associated with the first member is also included to substantially reduce vapor ingestion into the outlet of the tank. A second member is also included and operably associated with the plate to wet the plate with liquid stored in the tank and provide additional energy dissipation via friction.
In a third preferred embodiment of the present invention, a liquid storage tank is disclosed which has at least an outlet and a liquid management device. The liquid management device has a vortex suppression vane with a plate, to reduce ingestion of vapor, affixed to the top of the vortex suppression vane. Also, a bubble positioning vane is affixed atop the plate. The vortex suppression vane suppresses vortices that attempt to form in liquids as they are exiting the liquid storage tank. The plate, reduces the dip due to frictional energy dissipation as the liquid attempts to exit the tank. The bubble positioning vane works to ensure that the plate is wet with liquid at all times during emptying of the liquid storage tank. It also helps to position the bubbles away from the outlet to ensure that ingestion of gas into the outlet is non-existent or minimal.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.